CAMRT Radiographic Procedures: Body Cavities Questions and Answers 2 — Questions and Answers
Question 1: What is the correct centering for an AP supine abdomen (KUB)?
- Xiphoid process
- Iliac crest on the midsagittal plane (Correct answer)
- Symphysis pubis
- Sternal angle
Correct answer: Iliac crest on the midsagittal plane
Centre at the iliac crest to include diaphragm to symphysis pubis.
Must include diaphragm (for free air) and symphysis pubis (for bladder). Standard 35x43 cm detector. Exposure on arrested expiration.
Question 2: What preparation is required for an upper GI series with barium?
- No preparation
- NPO 6-8 hours and no smoking or gum chewing (Correct answer)
- Laxative bowel prep
- Drink 1 litre of water before
Correct answer: NPO 6-8 hours and no smoking or gum chewing
Fasting ensures an empty stomach for proper barium mucosal coating.
Smoking stimulates gastric secretions. If perforation is suspected, water-soluble non-ionic contrast is used instead. Effervescent granules for double-contrast technique.
Question 3: What must a properly positioned PA chest demonstrate?
- Only lung fields and heart
- Both lung fields, costophrenic angles, heart, mediastinum, thoracic spine, and apices free from clavicular superimposition (Correct answer)
- Only heart and great vessels
- Only lung bases and diaphragm
Correct answer: Both lung fields, costophrenic angles, heart, mediastinum, thoracic spine, and apices free from clavicular superimposition
All thoracic structures must be demonstrated with proper positioning criteria.
Minimum 10 posterior ribs on full inspiration. Clavicles equidistant from spinous processes. Scapulae laterally rotated. 72-inch SID, high kVp (110-130 kVp).
Question 4: What is the purpose of the erect abdomen radiograph?
- No difference from supine
- Demonstrates air-fluid levels and free air under the diaphragm (Correct answer)
- Only for kidney assessment
- Reduces radiation dose
Correct answer: Demonstrates air-fluid levels and free air under the diaphragm
The erect view shows gravity-dependent air-fluid levels and pneumoperitoneum.
Air-fluid interfaces indicate bowel obstruction. Free air beneath the diaphragm indicates perforation. Patient should be upright 5-10 minutes before exposure.
Question 5: What is the correct positioning for a lateral chest radiograph?
- Both arms at sides, facing detector
- Arms raised or held forward, left side against detector, true lateral alignment (Correct answer)
- Arms crossed, right side against detector
- One arm raised, one at side
Correct answer: Arms raised or held forward, left side against detector, true lateral alignment
Left side against detector minimizes cardiac magnification, arms out of the thoracic field.
Both arms raised to remove shoulder soft tissues. Central ray at T7. SID 72 inches. Femoral condyles should be superimposed. Full arrested inspiration.
Question 6: Why must both hemidiaphragms be shown on abdominal radiographs?
- No clinical significance
- Allows detection of free air and assessment of lower lobe pathology mimicking abdominal disease (Correct answer)
- Only important for chest imaging
- Required only post-surgery
Correct answer: Allows detection of free air and assessment of lower lobe pathology mimicking abdominal disease
Hemidiaphragm inclusion enables pneumoperitoneum detection and lower lobe pathology identification.
Free air appears as crescent lucency beneath the diaphragm. Basilar pneumonia can mimic abdominal pain. Field should extend to T9-T10.
CAMRT Radiographic Procedures: Body Cavities Questions and Answers 2
What is the correct centering for an AP supine abdomen (KUB)?